There are three facts which may help to remove the resistance which
naturally arises at any unusual sound when we are tired and want to
get rest.

One is that in almost every sound there is a certain rhythm. If we
yield to the sound enough to become sensitive to its rhythm, that,
in itself, is soothing. and what before was keeping us awake now
_helps us to go to sleep._ This pleasant effect of finding the
rhythm in sound is especially helpful if one is inclined to lie
awake while travelling in sleeping cars. The rhythm of sound and
motion in sleeping cars and steamers is, in itself, soothing. If you
have the habit of feeling as if you could never get refreshing sleep
in a sleeping car, first be sure that you have as much fresh air as
possible, and then make up your mind that you will spend the whole
night, if necessary, in noticing the rhythm of the motion and sound
of the cars. If you keep your mind steadily on it, you will probably
be asleep in less than an hour, and, when the car stops, you will
wake only enough to settle comfortably into the sense of motion when
it starts again. It is pleasant to notice the gentleness with which
a good engineer starts his train at night. Of course there is a
difference in engineers, and some are much more gentle in starting
their engines than others, but the delicacy with which the engine is
started by the most expert is delightful to feel, and gives us many
a lesson on the use of gentle beginnings, with other things besides
locomotive engines, and especially in our dealings with each other.

The second fact with regard to yielding, instead of resisting, in
order to get to sleep is that listening alone, apart from rhythm,
tends to make one sleepy, and this leads us at once to the third